The research seeks to identify functions of playground design which can be used to improve mental health treatment environments for children. It focuses on the playground as the child's work-play theater, part of his therapeutic milieu. Traditional playgrounds isolate equipment by type thus limiting and fragmenting experience. Children with difficulties in coding, decoding or encoding sensory experiences need an environment with multiple sensory modalities sequentially integrated so stimuli fall within their ranges of tolerance, and motivates them toward further development. A prototype playground will be designed based on the concept of an integrated, sequentially ordered play environment. It will be comprised of prototype units which can be separated and isolated, or linked to present an interrelated sequence of experience. Such sequences have been shown to motivate the child to various developmental behaviors. The behavior patterns of four groups of children (psychotic, mentally retarded, economically deprived, and normal) will be examined. Four playgrounds will be prefabricated and transported to sites of four collaborating agencies following a pilot study. At each agency children will be observed and tested: initially on their existing playground, then on equipment spatially isolated and on the playground equipment when integrated. Trained observers will record social interaction, task-oriented activities and gross motor activity. Visual documentation will also be recorded (video tape, time-lapse photography). Tests will be administered to measure both cognitive growth and creativity. It is hypothesized that the interrelated playground will be a therapeutic experience which motivates creative learning (improvements in information processing, increased social interaction; increased task- oriented activities and increased motivation. Results will be of use to people responsible for creating children's environments: (Planners, Programmers, Architects and Educators).